Diagnostic Considerations

Cutaneous T-cell lymphomas are T-cell proliferative disorders. Primary cutaneous lymphomas require distinction from histologically similar primary nodal ones because their clinical behavior, prognosis, and therapy are often different. In addition, a difference often exists between primary cutaneous and nodal lymphomas in the presence of specific translocations.

At times, disseminated infections such as leishmaniasis, leprosy, South American blastomycosis, coccidioidomycosis, and other deep fungal infections may mimic and require distinction from cutaneous T-cell lymphoma. Acne vulgaris, epidermal inclusion cysts, and insect bites may resemble folliculotropic mycosis fungoides.

Granulomatous mycosis fungoides with hypohidrosis may mimic lepromatous leprosy.
[73] Other conditions to consider in the differential diagnosis of cutaneous t-cell lymphoma include nonlymphomatous erythroderma and erythema neurolyticum migrans.

Olsen E, Vonderheid E, Pimpinelli N, et al. Revisions to the staging and classification of mycosis fungoides and Sezary syndrome: a proposal of the International Society for Cutaneous Lymphomas (ISCL) and the cutaneous lymphoma task force of the European Organization of Research and Treatment of Cancer (EORTC). Blood. 2007 Sep 15. 110(6):1713-22. [Medline].

[Guideline] Olsen EA, Whittaker S, Kim YH, et al. Clinical end points and response criteria in mycosis fungoides and Sézary syndrome: a consensus statement of the International Society for Cutaneous Lymphomas, the United States Cutaneous Lymphoma Consortium, and the Cutaneous Lymphoma Task Force of the European Organisation for Research and Treatment of Cancer. J Clin Oncol. 2011 Jun 20. 29 (18):2598-607. [Medline]. [Full Text].

A 40-year-old woman complained of a recurrent skin rash, which she described as "bug bites." Skin biopsy results demonstrated an atypical lymphoid infiltrate that was CD30 positive. The clinical picture and pathologic findings were consistent with lymphomatoid papulosis. This condition has a benign natural history, despite clonal gene rearrangement in some cases. Skin eruptions occur in self-limited crops, which do not require treatment.

A 42-year-old woman who had moved to the United States from Peru several year ago presented with an ulcerative lesion on her face near her nose, and destruction of her hard palate. Tissue biopsy revealed NK/T-cell lymphoma. Image courtesy of Jason Kolfenbach, MD, and Kevin Deane, MD, Division of Rheumatology, University of Colorado Denver School of Medicine.

Circulating atypical lymphocytes (Sézary cells) less than 5% of lymphocytes

B1

Circulating atypical lymphocytes 5% or more of lymphocytes (Sézary syndrome)

*Uncommon finding, usually not considered/investigated.

Table 5. Comparison of Staging Systems for CTCL

Clinical Stage

TNM (B) Stage

IA

T1 N0 M0

IIB

T2 N0 M0

IIA

T1 N1 M0

T2 N1 M0

IIB

T3 N0 M0

T3 N1 M0

III

T4 N0 M0

T4 N1 M0

IVA

T1 N2 M0

T2 N2 M0

T3 N2 M0

T4 N2 M0

T1 N3 M0

T2 N3 M0

T3 N3 M0

T4 N3 M0

IVB

T1 N0 M1

T2 N0 M1

T3 N0 M1

T4 N0 M1

T1 N1 M1

T2 N1 M1

T3 N1 M1

T4 N1 M1

T1 N2 M1

T2 N2 M1

T3 N2 M1

T4 N2 M1

T1 N3 M1

T2 N3 M1

T3 N3 M1

T4 N3 M1

Table 4. International Society for Cutaneous Lymphoma/European Organization for Research and Treatment of Cancer tumor-node-metastasis-blood revised classification for mycosis fungoides and Sezary syndrome

Skin

Involvement

Node

Involvement

Viscera

Involvement

T1

Patchy or plaquelike skin disease involving ≤10% of the skin surface area

N0

No abnormal lymph nodes

M0

No visceral organ involvement

T2

Patchy or plaquelike skin disease involving ≥10% of the skin surface area

N1

Histopathology Dutch Gr 1 or NCI LN 0-2

M1

Visceral organ involvement

T3

Tumors are present ≥1 cm in diameter

N2

Histopathology Dutch Gr 2 or NCI LN 3

MX

Abnormal visceral site; no histologic confirmation

T4

Erythroderma ≥80% of body area

N3

Histopathology Dutch Gr 3-4 or NCI LN 4

Blood

Involvement

Nx

Abnormal lymph nodes; no histologic confirmation

B0

≤5% of peripheral blood lymphocytes are Sezary cells

B1

>5% of peripheral blood lymphocytes are Sezary cells but do met B2 criteria

Robert A Schwartz, MD, MPH Professor and Head of Dermatology, Professor of Pathology, Pediatrics, Medicine, and Preventive Medicine and Community Health, Rutgers New Jersey Medical School; Visiting Professor, Rutgers University School of Public Affairs and Administration

Francisco J Hernandez-Ilizaliturri, MD Professor of Medicine, Department of Medical Oncology, Associate Professor of Immunology, Department of Immunology, Chief, Lymphoma and Myeloma Section, Director, The Lymphoma Translational Research Program, Roswell Park Cancer Institute, University of Buffalo State University of New York School of Medicine and Biomedical Sciences

Günter Burg, MD Professor and Chairman Emeritus, Department of Dermatology, University of Zürich School of Medicine; Delegate of The Foundation for Modern Teaching and Learning in Medicine Faculty of Medicine, University of Zürich, Switzerland